The present invention relates generally to flextensional transducers, and more particularly to a substrate for a flextensional transducer.
Fluid drop ejectors have been developed for ejecting droplets of a flowable material. An example of a fluid drop ejector includes a flextensional transducer. As illustrated in FIGS. 1A and 1B, a conventional flextensional transducer 90 includes a body or substrate 92, a flexible membrane 94 having an orifice 96 defined therein, and an actuator 98. The substrate defines a reservoir for holding a supply of flowable material and the flexible membrane has a circumferential edge supported by the substrate. The actuator includes a piezoelectric material which deforms when an electrical voltage is applied. As such, when the piezoelectric material deforms, the flexible membrane deflects causing a quantity of flowable material to be ejected from the reservoir through the orifice.
One application of a flextensional transducer is in an inkjet printing system. As such, the inkjet printing system includes a printhead having a plurality of flextensional transducers that eject droplets of ink through orifices or nozzles to form an image on a print medium. Fluid or ink is delivered to each of the flextensional transducers through fluid channels formed in a substrate of the flextensional transducers. Existing methods for forming fluid channels in the substrate, however, are relatively slow and expensive, are difficult to control, and/or expose materials which are reactive with ink.
Accordingly, there is a desire for accurately and efficiently forming a substrate for a flextensional transducer.
One aspect of the present invention provides a flextensional transducer. The flextensional transducer includes a substrate having an etch stop layer interposed between a first layer and a second layer, a flexible membrane supported by the second layer of the substrate and having an orifice defined therein, and an actuator provided on the flexible membrane and adapted to deflect the flexible membrane. The substrate has an opening formed through the first layer and a hole formed through the etch stop layer and the second layer such that the hole through the etch stop layer and the second layer of the substrate communicates with the opening through the first layer of the substrate and the orifice in the flexible membrane.